Are my cylinders ok

waterdawg69

Petty Officer 1st Class
Joined
Jul 6, 2006
Messages
204
i have a 1968 or 1969 160hp mercrusier 4.1 liter, i did a compression check and all my cylinders are 125psi 130 psi are they ok?
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: Are my cylinders ok

Sounds like it but I am sure more knowledgeable folks will chine in with better info. 8)
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Are my cylinders ok

A little tired, but they still have some life in them.....
Below 100# would be unacceptable.....
They are all close together, #'s wise....
That's good.......;)
 

waterdawg69

Petty Officer 1st Class
Joined
Jul 6, 2006
Messages
204
Re: Are my cylinders ok

is there a way to boost compression like using diff oil ?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Are my cylinders ok

140 is book compression. 125 to 130 is VERY acceptable.
 

mike176

Petty Officer 1st Class
Joined
Feb 18, 2007
Messages
202
Re: Are my cylinders ok

Sound good to me. The fact that they are close is a very good sign. I would not be worryed about that at all. I would not try using diff oil to boost it!! change the oil and replace one quart with lucas oil stabilizer. I work for a police fleet and we swear by that stuff, seen it do amazing things.
 

mike176

Petty Officer 1st Class
Joined
Feb 18, 2007
Messages
202
Re: Are my cylinders ok

i would also sigjest a decarb with some deepcreep. i do that once a year for my boat.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Are my cylinders ok

spring is here, i'd think that gettin out and wearing it out some more would be in order.....:), themz numbers are better than mine. i'm beside myself. i been out once and now got a darn cold snap comin with below freezein temp...i'm bummed. besides. ya know what they say, lack of use will kill it faster than usein it.......good numbers man......what kinda boat ya pushin with that fine 160hp......
 

waterdawg69

Petty Officer 1st Class
Joined
Jul 6, 2006
Messages
204
Re: Are my cylinders ok

its a 1969 lake flight fish and ski, i bought of a guy that could'nt get it running. i brought it home and all that was wrong with it was the fuel pick up was clogged, and i bought it for $450.00 cash. everything work from tilt/trim to gauges. lights everything. paint is in great conditon and the floor was not rotted out. even has a stereo in. its black in color with green interior, but don't care for the green interior. but it gets me out there.
 
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